The present invention relates to an estimating apparatus and an estimating method that estimate process of therapy using a laser catheter.
Atrial fibrillation is known as a kind of tachyarrhythmia. A hyperexcited site, which generates an electrical pulse, appears in the vicinity of a root portion, in which a pulmonary vein and a left atrium are connected, and the left atrium minutely vibrates and contracts because of the electrical pulse stimulation, to thereby cause an atrial fibrillation.
As an atrial fibrillation therapeutic method, the inventors have been proposed application of photodynamic therapy (hereinafter, referred to as “PDT”.) (for example, see Patent Document 1.). In PDT, a cardiac-muscle tissue, which has absorbed photo-sensitive pharmaceutical, is irradiated with an excitation light by using a laser catheter, to thereby generate singlet oxygen. The singlet oxygen as a strong oxidizer insults a cardiac-muscle tissue, which surrounds the hyperexcited site, to thereby form an electric-conduction block, which blocks conduction of the electrical pulse from the hyperexcited site to the left atrium. As a result, an electric conduction between the hyperexcited site and the left atrium is blocked, and an abnormal vibration and contraction of the left atrium is inhibited.
Photo-sensitive pharmaceutical has a property of selectively accumulating in a certain tissue. In view of this, in general, after a predetermined time (for example, 8 to 48 hours) passes after photo-sensitive pharmaceutical is administered in a patient, when the state where the photo-sensitive pharmaceutical concentration is high in a therapy-target tissue and the photo-sensitive pharmaceutical concentration is low in other tissues and blood is established, that is, when the state where a so-called photo-sensitive pharmaceutical contrast is high is established, irradiation with the excitation light is started. Further, recently, PDT, in which the accumulating property of photo-sensitive pharmaceutical is not used and in which irradiation with the excitation light is started when photo-sensitive pharmaceutical is delivered to a therapy-target tissue by blood, is proposed.
Patent Document 1: WIPO Publication No. 2008/066126